Treatment of paper pulp



Nov. 4, 1941. K. A. THORSEN TREATMENT OF PAPER PULP I Filed Dec. 29, 1938 3 Sheets-Sheet 1 F1 INVENTOR:

VIII/III r 2 N E m 0N R m 5 mm R .D N A N n s m w K Nov. 4, 1941.

K. A. THORSEN 2,261,315

TREATMENT OF PAPER PULP Filed Dec. 29, 1938 s Sheets-Sheet 2 l NVENTbR.-- K RISTEN ANDREASTHORSEN by ATTORNEY Nov. 4, 1941. K. A. T HORSEN 2,261,315

TREATMENT OF PAPERPULP Filed Dec. 29, 1938 3 Sheets-Sheet 3 V///1 I Q n '//l lZZ/A 75 g 77 E m V Y J 5 INVENTORJ KRlSTENA'NDRASTHORSEN ATTORNEY Patented Nov. 4, 1941 '3 UNITED" STATES PATENT p g TREATMENT OF PAPER PULP Kristen Andreas Thorsen, GrenobIeQFrance ApplicationDecember 29, 1938,lS erial No. 248,289 In Germany January 11, 1938 4 Claims. gel. ice-99) The present invention relates to animprovement in the treatment of paper pulp and-has for its object to facilitate the tearing up'of the paper pulp. Y It is known to those skilled in the art that paper or cardboard pulp is delivered in a substantially dry. state either in sheets'of 60 to 70 cm. in width and 75 to 100 cm. in length, or in the form of spools or reels which often contain several hundred metres, the latter method being used more and more in certain important paper pulp producing countries. Before the pulp, is re-. fined in suitable machines, the pulp must first be cut or torn ,up into small pieces :of lengths, for example of 40 by 40 mm. Oneof the best known devices of the prior art for Cutting or tearing paper pulp comprises a pair of rotating cylinders, each provided with toothed discs engaging between the discs of the other cylinder and adapted to cut up the sheet of pulp which is caused to pass between said cylinders. -Whenthe paper pulp is in sheets of '75 to 100 cm. in length, the strips issuing from the tearing up machine present a rather important drawback for further treatment of the paper pulp, and this drawback makes the use of such tearing up by means of discsyutterly impossible in the case the pulp is delivered in reels, since the 'obtained strips would in this case be several hundred metres long. 1 a

The object of the present invention is to en able the tearing up into small pieces paper pulp delivered in the form of sheets or reels, by means of the abovementioned machine provided with discs. This result is obtained, according to the invention, by the fact that the paper pulp is provided with perforations in the form of slots inclined with respect to the longitudinal direction of the sheet and arranged along adjacent rows corresponding to the discs of the tearing cylinders. v By making these perforations sufiiciently close to 'each other, it will be understood that after passing through the disc tearing up machine, the pulp'will be reduced into pieces, the width of which corresponds to the spacing between the discs of a cylinder, and the length of which corresponds to the distance between the subsequent perforations of the same row. According to the present invention, these perforations may be made in the paper pulp either during" its preparation, preferably in a phase when the pulp is still moist and consequently less resistanu'or at the moment .of its use, immediately before the tearing up. I i

-IBy way of ,example,'there hasbeen described below and represented in the accompanyingdrawings a number of embodiments of a-device for perforating the pulp tion respectively a disc tearing up machine combined witha, perforating device according to the present invention. x

. Figures 3 and 4 represent inlongitudinal secforating and tearing up the dry pulp delivered in reels, the machine consisting ina tearing up device, comprising discs 3-4 and a perforating device arranged on the path of the sheet ofpulp. in front of the tearing up device. The perforate, ing device comprises two pairs of cylinders 20-21 and 2223 arranged in succession on the path of-the sheet of pulp .24. The upper cylin ders 20 and 22 of the two pairs of cylinders are provided with teeth25-26 with a fiat and 'very narrow cross section, arranged along generating .lines of these'cylinders and along circular rows. The rows of teeth 25.25 of the cylinders .2ll--22. correspondingv respectively to the toothed discs.

The low-- er cylinders 2l-.--,23 are provided with grooves 2'|-28 corresponding to the teeth 25-26 which 34 of the tearing up cylinders l-Z.

engage in'said grooves during the-rotation of the cylinders. These cylinders may for instance be hollow, the grooves of the cylinders 21- 23 being formed by drilling holes into the cylinder shells, while larger apertures 29 are provided in the cylinder shells (Figure 2) for permitting. the withdrawal of the particles of pulp which may have penetrated into the cylinders through the holes 21-28. The toothed cylinders 20-22 h and the perforated cylinders 2l-23 carry, be-

tween the rows of teeth or holes, circular grooves 30-32, 3I-33 in which are arranged blades in the form of combs 34-36, 3531 fixed to the cross-members 38-40, 394I and adapted to guide the pulp between the perforating cylinders and remove it from the teeth and holes of these cylinders. The cross-members 39-- 4 I further .carry the blades 5, 6 acting as scrapers inthe disc tearing up device I2 arranged after the perforating cylinders and at the exitofwhich according to the present invention. a

Figures 1 and 2 represent in longitudinal sectional elevation and in partial transverse secders 2022, the pinion 41 transmitting the drive i to the tearing up cylinders l, 2 through the pinions 58, 52.

The embodiment of the perforating device described above and represented in Figures 1 and 2 may be replaced by that represented in Figures 3 and 4, in which the perforator consists of a pair of similar cylinders 53, 54 each provided, on one hand, with circular rows of transverse teeth with a flat cross section, 55, 56, corresponding to the discs of the two tearing up cylinders respectively, and, on the other hand, with circular rows of holes 51, 58 arranged in the intervals between the teeth, the holes of each of the cylinders being offset circumferentially with respect to its teeth and correspondingly to the teeth of the other cylinder, so that the teeth of each cylinder will engage the holes of the other during their rotation, thereby forming in the sheet of pulp I the same perforations as the device disclosed in Figures 1 and 2.

As in the embodiment described above, the toothed cylinders carry, in the intervals comprised between the rows of teeth, circular grooves 59, 60 engaged by the comb blades BI, 62 which act as scrapers and removing from these cylinders the pulp which has a tendency to adhere to the cylinders.

A third embodiment of a perforating device ap-. plicable to the dry pulp and capable of being combined, as described above, with a disc tearing up device, has been represented in Figures 5 and 6. This latter device comprises a single rotating toothed cylinder 63 provided with two series of circular rows of transverse teeth 64, 64', 64" and 65, 65, 65" offset circumferentially with respect to one another according to the perforations desired in the sheet of pulp. The two offset series of teeth corresponding to the discs of the two tearing up cylinders respectively. This toothed cylinder 63 is mounted eccentrioally in a hollow cylinder 66 rotating at the same circumferential speed as the first cylinder and provided with a series of holes 61, 61', 6'!" and 68, 68, 68 corresponding to the teeth of cylinder 63, which engage these holes in the vicinity of the lowermost generating line of the two cylinders. In order to maintain the sheet of pulp well applied against the teeth of cylinder 63, which pass through the holes of the hollow cylinder 66, a second hollow rotating cylinder 69 is arranged below the cylinder 66, and is provided with a series of holes 10, I9, 19 and H, 7|, 1| corresponding to the teeth of cylinder 63 and engaged by these teeth during rotation. Scrapers 12, 13 rest against the two hollow perforated cylinders 66 and 69 in order to remove the perforated pulp tending to adhere to the cylinder. The hollow perforated cylinder 66 which rotates the toothed cylinder 63, provides a most satisfactory guide for the sheet of pulp 24 as it passes through the perforator, as well as a correct detaching of the sheet of pulp from the teeth of the cylinder 63.

A fourth embodiment of the present invention which is particularly advantageous for the perforation of the sheets is represented in Figures 7 and 8.

A cylinder 12 provided with thin teeth 13 is connected to another cylinder 14 by means of the gears 15.

The hollow cylinder 74 is provided with holes 16 engaged by the teeth 73. Suitable openings I1 provided at both cylinder ends permit the withdrawal of the small particles of pulp which might have penetrated inside the cylinder through the holes 16 by means of the teeth 13.

The cylinder 12 is yieldably applied against the cylinder 14 by means of movable bearings 18, springs 19 and the pressure screws 86. An abutment 8| has been provided for maintaining a very small distance between the two cylinders.

Against the cylinder '14 is yieldably applied a roller 82 by means of the movable bearings 83, the springs 84 and the pressure screws 85.

The sheets 86 arriving between the roller 82 and the cylinder 14 are strongly applied against the latter in order to ensure a good adherence and prevent a rolling of the sheets transversely over themselves under the action of the teeth 73 when the latter penetrate into the apertures 16. For the same reason, the cylinder 74 has been provided with a rough surface 86a (Figure 8).

For facilitating the penetration into the sheets and preventing any sliding motion against the surface of the latter, the teeth 13 are constructed in the form of a saw 81.

When the sheets 86 pass between the cylinders 12 and 14 where they are pierced by the teeth 13, the sheets cling to the teeth 13 and follow the cylinder 12. For detaching them from the cylinder, there has been provided suitably bent guide members 88.

Ihese guide members are maintained in circular grooves 89. To this effect, the teeth 13 have been arranged in two portions 90 and 9| for permitting the passage of said guide members. The latter are very thin, and the spacing of the two portions 90 and 9| is also very small. When these portions have pierced the sheets, the line 92 corresponding to the spacing, which have not been subjected to the action of the teeth, will tear up easily under the effect of the two portions 99 and 9|.

The guide members 88 progressively detach from the teeth I3 the sheets 86 which thereafter penetrate between the guide members 5, 6 and the separating discs 3 and 4 by which they are delivered as rectangular pieces.

A pinion 93, which may be driven by any suitable motor, meshes both with the gears of cylinders I2 and 14, and with those of the separating discs 3 and 4.

What I claim is:

1. Machine for perforating a sheet of paper pulp to be fed through a disc tearing-up machine, comprising at least two parallel rotating cylinders equipped with a system of teeth and cavities cooperating with each other, said teeth and cavities being inclined in respect to the base circiunferences of the said cylinders and forming, in their entirety, a series of contiguous circular rows the number of which corresponds to that of the discs of the said tearing-up machine and which are staggered in respect to each other circumferentially of the cylinders, the ends of the two adjacent rows facing each other extending at least up to a common circumferential plane parallel to the bases of said cylinders.

2. Machine for perforationg a sheet of paper pulp to be fed through a disc tearing-up machine, comprising four parallel rotating cylinders coacting in pairs, one of the cylinders of each pair being equipped only with teeth and the other cylinder of the same pair only with cavities corresponding to the teeth of the first cylinder of the pair, the said teeth and cavities being inclined in respect to the base circumferences of the said cylinders and forming, on the respective cylinders, circular rows separated by intervals and disposed in such a manner that the teeth of a given row of one of the toothed cylinders are opposite the intervals between the teeth of two adjacent rows of the other toothed cylinder, the ends of the teeth of the said row of the first cylinder extending at least as far as the two circumferential planes passing between the opposite ends of the teeth belonging to the said two adjacent rows of the other toothed cylinder, the total number of the rows of teeth of the two toothed cylinders corresponding to that of the discs of said tearing-up machine; a series of grooves made in said cylinders between the rows of teeth and of cavities, respectively, rakes in the form of combs disposed in the said grooves for detaching the sheet of pulp from the perforating cylinders.

3. Machine for perforating a sheet of paper pulp to be fed to a disc tearing-up machine, comprising two coacting cylinders each of which is equipped with circular rows of teeth and of cavities, respectively, slanting in respect to the base circumferences of the said cylinders, the rows of teeth being separated, on each cylinder, by ranges of cavities staggered in the circumferential direction in respect to the rows of teeth,

the ends of a given row of teeth extending at,

least as far as the two circumferential planes passing through the opposite ends of two rows of cavities located on either side of the given row of teeth, the total number of the rows of teeth and of cavities of one of these cylinders corresponding to the number of discs of the tearing-up machine, a series of circular grooves made on the said cylinders between the rows of teeth and comb-shaped rakes disposed in said grooves for detaching the sheet of paper pulp from the perforating cylinders.

4. Machine for perforating a sheet of paper pulp to be fed into a disc tearing-up machine, comprising two tangent hollow cylinders each equipped with circular rows of cavities slanting in respect to the base circumferences of the said cylinders, the said rows being alternately staggered in a circumferential direction and their number corresponding to that of the discs of the tearing-up machine, the ends of the cavities of a given row extending at least as far as the two circumferential planes passing through the opposite ends of the cavities of two adjacent rows; in the interior of one of said hollow cylinders an eccentric cylinder equipped with circular rows of teeth the number and arrangement of which correspond to those of the rows of cavities of the said hollow cylinders so as to cooperate therewith, means for rotating the said three cylinders at the same speed, and rakes bearing against said cylinders for detaching therefrom the perforated sheet of pulp.

KRISTEN ANDREAS THORSEN. 

